The invention relates to a signal-processing system, and also to the individual components of this system per se. The invention relates in particular to a signal-processing system that can obtain signals within an operating range of a user on the basis of which switching states can be set that correlate with actions, gestures, positions or other actions applicable to the switching state for the user.
In the present context the term “sensor” in particular means switches, elements for detecting pressure, temperature, brightness, and forces as well as devices capable of detecting states and if required changes in state. To date it has been usual to detect switch actions of a user via sensors, switches in particular. These sensors are typically connected to a controller that processes the switching signals.
An effort is normally made to detect corresponding signals with the least possible circuitry and cabling outlay. This applies in particular white goods (e.g. washing machines, dishwashers, stoves, etc.) as well as motor-vehicle equipment and fittings, e.g. motor-vehicle seats, steering wheels, etc. Different sensors, which for example create an overall physical image of specific situations, must be interconnected. This is done via bus systems, or if required also wirelessly by radio technology, the sensors being in some cases equipped with their own power supply (batteries, power cells).
The object of the invention is to provide solutions that make it possible to solve a number of sensor problems in a limited space in a cost-effective manner with relatively little circuitry.
This object is attained according to the invention by a sensor system for generating control signals that are employed for setting switching states, whereby a user located in the region of the sensor system acts as signal-transmitting structure, with:
a first detector comprising a sensor, a local-key circuit and a signal-outputting circuit for generating a tell signal including data corresponding to a sensor event detected by the sensor,
a second detector also comprising a sensor, a local-key circuit and a signal-outputting circuit for generating a tell signal including data corresponding to a sensor event detected by the sensor,
a signal requester comprising an interface that outputs seek signals into the user and receives tell signals from the user,
the local-key circuit assigned to each detector being configured in such a way that the tell signal carries information content that enables assigning of the tell signal to the respective detectors.
This makes it advantageously possible to detect the signals of several sensors without special direct wiring between the detectors and the signal requester being required for this very purpose.
The tell signal is preferably time-offset from the seek signal. It is possible for the individual detectors to provide different delay windows to enable substantially collision-free data feedback. The length of delay can constitute the identifier specified by the local-key circuit.
It is also possible to emit the tell signal at least phase-wise at the same time as the seek signal. The tell signal can be routed back by impedance modulation to the interface of the signal seekers.
One of the detectors can be addressed preferably by the seek signal. Power can be supplied to the detectors via the seek signal.
In generating the sensor signal as proximity sensor signal it is possible in particular to generate the sensor signal, e.g. via level detection via the seek signal.
In using the inventive sensor system in a motor-vehicle seat in particular it is possible for at least one of the sensors to be a pressure sensor. The sensor system can be at least partially integrated directly into the motor-vehicle seat or seating space. It is possible in particular to provide the signal requester in the region of the center console so that it transacts a signal dialog via the thighs of the seated user. The pressure sensors sit at the appropriate points of the seat, in particular as a sewn-in or mounted flat module. Seat occupancy can be determined via the sensor system. An air-bag system can be controlled according to this seat occupancy discrimination.
The system can comprise several signal requesters that can also dialog with one another, for example for determining addresses of the detectors.
The interface preferably comprises a transmitter electrode and a receiver electrode, both electrodes being spaced from one another.
The local key of the respective detectors can be specified preferably by the signal requester. The response characteristic of the respective sensors, in particular a response delay, can be specified preferably via the signal requester.
The invention operates wirelessly, contact-free and without the detectors requiring their own power supplies. In contrast to a selective mode of operation the invention advantageously operates simultaneously. People and their actions can particularly be an essential constituent of the sensor network.
The detectors can include physical pickups for power, voltage, temperature, pressure, moisture, and vibration that are powered only by the query signal. The detectors can also be configured such that they are capable of “energy harvesting,” whereby the electric supply is achieved by converting mechanical or other physical environmental effects (piezo, induction etc.) Such sensors are often fitted with a communications mechanism. Using protocols it is possible to set and/or query these sensors also cyclically according to a specific scheme.
With the inventive concept it is possible to build quasi self-organizing sensor networks by cost-effective circuits, there being advantageously practically no costs for cabling, plugs or batteries. The network can operate simultaneously and can be powered and queried wirelessly. This can eliminate expensive (and thus cost-intensive) protocols. Due to the simplicity of the circuit layout it is possible in the future to print such sensors on polymer films and to attach these by adhesive at the points to be monitored. The invention works without wires and is capable of wirelessly transmitting the sensor information simultaneously to an evaluation unit (server) that tends the sensors in its vicinity by electric (or electromagnetic) alternating fields. Changing the field strength makes it possible to switch sensors on and off, or to perform switching procedures. It is also possible for the sensors to be activated by a person in their proximity. This can happen as an intentional conscious action or automatically by a certain spacing of the sensors.
The invention is multifunctional. It uses a metallic or otherwise conductive connection as supply, sensor and communication element. Also conductive fibers (e.g. carbon) are used for this purpose. Since all sensors operate simultaneously it is possible for the server to create a status diagram that can be evaluated for example by way of Fourier transform analysis (FFT). Since the sensors are powered (and queried) by at least one electric (or electromagnetic) field, changes in the dielectric can also be made and evaluated. The invention therefore preferably has a level-responsive operating method (it can however also work by frequency or phase shift and pulse widths). The invention also allows several servers to be utilized at the same time. Since the sensors are powered by the electric field and queried at the same time, the latter can be checked continuously for correct function (sensor “OK” signal). Due to Faraday effects it is possible to act within an inertial space, e.g. inside a machine. The sensor transmission function does not reach the outside and accordingly cannot disturb other appliances, something not always guaranteed with radio.